Mechanical Engineering

Solar energy is an economical alternative for today’s energy demand in comparison with other energies. Solar air heater is used for heating the air which in turn is used for drying the agricultural products. The objective of this paper is to design, develop and perform a detailed experiment and analyze the solar assisted drying system (SADS) for drying tealeaves. Green tealeaves plucked directly from the plantations are soaked in warm water for few minutes. Water is drained out; wet leaves are dried using the SADS consists of drying chamber maintained at a temperature of 55°C and pressure of 3Kg/cm2 through solar collectors. The initial weight of the green tea leaves is of 100 gms, which is reduced to 38gms in an hour.

The conventional solar still is modified by thermal energy storage material (Fly ash particles) to absorb the maximum amount of solar energy during shiny hours to increase the evaporation rate. In this work, fly ash is used effectively to store the thermal energy and also support the still to minimize the heat loss through bottom and side wall of the solar still. The fly ash is effectively used in the solar still to maintain the greater temperature difference between the glass inner surface and water by absorbing the excess amount solar energy during shiny hours. So, evaporation rate increases in the solar still. The quantity of the fly ash in the basin will influence the productivity of the still and other parameters like water temperature‚ glass surface temperature and vapour temperature etc. In this work, the experimental work has been conducted for various quantity of water and various depth of fly ash to find the optimum quantity of water and depth of fly ash in the basin. Finally, the performance of the modified solar still is compared with the conventional solar still under the same climate conditions. The productivity of the modified still is improved by 71 %.

The concept of CNC (Computer Numerical Control) in machine tool evolved at the Massachusetts Institute of Technology (MIT), USA between the year 1947 to 1952 for the manufacture of complex & accurate helicopter blades. Since then, this technology has been applied to many different types of machines & machine tools. Now a days the CNC machines have found adoption of by many industries. They have become virtually indispensible in many manufacturing industries because of their many advantages and easy management & reliability. In the face of stiff competition, higher cost of labour & higher rejection of parts, CNC machines proved to be a boon for any manufacturing industry, be it a metal cutting industry, metal forming industry & any other manufacturing industry. Now a days no industrialist can think of putting up an industry without CNC machines, such are their importance & advantages. Talking of Cellular Manufacturing Systems, where a cell of machine tools & other facilities like job movement arrangement etc are created to process a machine part or component from the input of raw material to the finished part. One cannot think of designing such a cell without any CNC machine . CNC machines are part & parcel of Cellular Manufacturing Systems. Rather, they form the backbone of Cellular Manufacturing Sytems.

In our country most of the population has agriculture as a primary source of income. Agricultural output consist of 16% of India GDP but in most parts of our country there is scarcity of water. To give boost to agriculture the earliest leaders of the country had given primary importance to irrigation projects. But day by day it’s becoming need of the hour to utilize micro irrigation techniques like drip and sprinkler irrigation. In our country most of the farmers utilize conventional process of pipe collection. But it effects the life of pipes, while collecting the pipes it forms scratches, minute holes, bends and while utilizing next time its efficiency has been decreased so these paper deals with the application of a simple mechanism to coil the pipes and collect it without bending or forming twist and increasing its efficiency and long life. It deals with very basic but un-noticed problem related to drip irrigation pipes.

Air conditioning system is essential for maintaining thermal comfort in indoor environments, especially for hot and humid climates. Today, air conditioning, comprising cooling and dehumidification, has become a necessity in commercial and residential buildings and many of the industrial processes. It accounts for a major share of the electric energy consumption. Therefore, there is tremendous potential to improve the overall efficiency of the air-conditioning systems in buildings to reduce the uses of energy. In this present research work, begins with a review of the type of losses especially conduction loss, recent novel devices that enhances the energy efficiency. Lastly, the research presents efficient cooling strategies and R-factor of building material with minimization of conduction losses that reduce the primary energy utilization for cooling.

There is a growing demand for the need of alternative fuels for transportation. Increasing the efficiency and reducing the exhaust gases in engines have been dominant in the fields of research. The exhaust gases contain numerous pollutants that are extremely harmful though in chronic conditions. Hence, Electromagnetic engines were created that uses the combined power of an electromagnet as well as a permanent magnet. While these engines have already proven their worth as alternative sourced engines, non-polluting and eco-friendly, the current challenge is to make them more efficient, reliable and cost effective.

As maintenance play key roles for smooth production especially in the textile industry. Nowadays the effective maintenance model is not an option but it is the necessity of industries. It aims to reduce unplanned stoppage, breakdowns accidents and losses obstructing equipment effectiveness. Therefore by implementing TPM the industries can increase their equipment effectiveness and productivity. This present research work is aimed at implementation of Total productive maintenance in Indian textile industries. In the yarn section the TPM model is first introduced and staff members are trained according to the eight pillars of TPM. The need for driving down costs, integrating every activities and available resources of a company, empowering the employee to make decision, eliminating waste generated by failure across the value adding process, shortening of production lead time and delivery of quality assured services and products have been given due attention.

In modern engine design, to reach a more compact and optimized cooling system, exploiting nucleate boiling in thermally critical regions is required. Several studies have attempted to enhance the nucleate boiling heat transfer. This paper reviews the most important issues (i.e. surface roughness, composition of the liquid, electric field, vibration, orientation of the heated surface, surfactant addition, pressure and velocity) and their effects on nucleate boiling heat transfer.

In the present work the effect of heat treatment on wear behavior of AISI310, AISI253ma and AISI410 Silicon steels are investigated. The chosen materials were heat treated at 8500C and kept at this temperature for a soaking period of 60 minutes, cooled by quenching in air until the room temperature is attained. As-cast materials were also taken for tests for comparison. The wear tests were carried out on above three materials with three parameters viz., velocity, load & time by keeping two of the parameters as constant and varying the other one in each test.

The effect of penstock diameter on shaft power was studied as part of an ongoing development of a simplified pico-hydropower system with water recycling. The speeds of the turbine and alternator shafts and volume of water displaced were measured for each penstock diameter and nozzle area ratio. The shaft power, flow rate and efficiency of the turbine were computed. The mean efficiencies were 0.776 and 0.510 for penstocks diameters 0.0762 and 0.0381 m respectively. Hence, larger penstock diameters with small nozzle area ratios favor optimal system operation. The results show that the system can potentially impact Nigeria’s energy mix positively